Propagation and Rate-Aware Cell Switching Optimization in HAPS-Assisted Wireless Networks

TL;DR

This paper introduces a realistic, multi-objective cell switching optimization approach for HAPS-assisted wireless networks, balancing energy efficiency with user connectivity and data rate performance under practical propagation conditions.

Contribution

It redefines cell switching modeling to include realistic propagation effects and formulates a multi-objective optimization problem solved via two methods, validated through system-level simulations and emulation.

Findings

WSM reduces rate degradation by up to 70% for high-loss indoor users.

The approach eliminates 44% rate drop for low-loss indoor users.

Proposes a realistic, multi-objective framework for energy-efficient cell switching in HAPS networks.

Abstract

Cell switching is a promising approach for improving energy efficiency in wireless networks; however, existing studies largely rely on simplified models and energy-centric formulations that overlook key performance-limiting factors. This paper revisits the cell switching concept by redefining its modeling assumptions and mathematical formulation, explicitly incorporating realistic propagation effects such as building entry loss (BEL) and atmospheric losses relevant to non-terrestrial networks (NTN), particularly high-altitude platform station (HAPS). Beyond proposing a new cell switching strategy, the conventional energy-focused problem is reformulated as a multi-objective optimization framework that jointly minimizes power consumption, unconnected users, and data rate degradation. Through this reformulation, the proposed methods ensure that energy-efficient operation is achieved without compromising user connectivity and data rate performance, thereby inherently supporting sustainability objectives for sixth-generation (6G) networks. To solve this reformulated problem, two complementary approaches are employed: the weighted sum method (WSM), which enables flexible and adaptive weighting mechanism, and the {{\epsilon}-constraint-inspired method ({\epsilon}CM), which converts connectivity and rate-related objectives into constraints within the conventional energy-focused problem. Moreover, unlike prior work relying only on simulations, this study combines system-level simulations with Sionna-OpenAirInterface (OAI) based emulation on a smaller network to validate the proposed cell switching concept under realistic conditions. The results show that, compared to the conventional approach, WSM reduces rate degradation for up to 70% for high-loss indoor users and eliminates the 44% drop for low-loss indoor users.